The U.S. Pat. No. 4,528,848 discloses an apparatus for continuous gravimetric metering of pourable material which is supplied through a charge opening into pockets of a rotor arranged in a housing and rotatable about a vertical axis the material being removed from the pockets by applying pressurized air through a discharge opening arranged off-set in rotational direction of the rotor in respect of the charge opening. The housing is supported pivotally about an essentially horizontal axis and is connected to a force measuring device arranged remote to this axis. At the charge opening and the discharge opening an elastic connecting member each is provided. The horizontal axis extends through the centers of the elastic connecting members such that forces caused by twisting upon loading of the metering apparatus are of no influence.
With such a metering device a high accuracy may be achieved; however it is relatively complex. Furthermore, with pourable material having a high humidity or sticky pourable material dome formation may take place in the pockets of the rotor resulting in an insufficient throughput of pourable material and falsification of the measuring values.